In a blender, combine the Brown's milk, cream cheese and salad dressing mix. Cover and process until smooth. Place potatoes in an 8-in. square baking dish coated with cooking spray; top with milk mixture. Cover and bake at 350 degrees for 35 minutes.
Sprinkle with cheddar cheese and bacon. Bake, uncovered, 8-10 minutes longer or until cheese is melted and potatoes are tender.